Method for manufacturing hollow bodies of steel alloys, or other metals



May 5, 1925. 1,537,041

T. BECKER METHOD FOR MANUFACTURING HOLLOW BODIES OF STEEL, ALLOYS, OR OTHER METALS Filed Aug. 1921 A fi l j (1 J9 M Patented May 5, 192 5.

- UNITED STATES PATENT OFFICE.

THEODOB BECKER, F DUSSELDORF. GERMANY.

METHOD non MANUFACTURING HOLLOW EomEs or STEEL. ALLOYS, on OTHER METALS.

Application filed August 30, 1921.

To all whom it may concern Be' it known that I, THEODOR BECKER, director, residing'at Dusseldorf, Germany, have invented certain new and useful Improvements in a Method for Manufacturing Hollow Bodies of Steel, Alloys, or Other Metals (for which I filed application in Germany, August 1, 1918), of which the following is a specification.

This invention relates to the manufacture of seamless tubes and other hollow bodies, and its object is to prevent disadvantages arising from present methodsfor making certain classes of seamless tubes.

The piercing of solid ingots or rolled rounds of iron, steel, alloys and other metals into hollow. bodies has up to the present been carried out after the cast ingots or other rounds have been generally cooled down to the atmospheric temperature and reheated again in suitable furnaces to a more or less suitable temperature for piercing the ingots in Mannesmann-, Stiefelor the like rollingor spinning-piercers or by means of pressing with Ehrhardt, Sarson-or the like apparatuses.

that during the operation of piercing, the

inner metal structure is more or less liable to strain or stress according to the influence of action of cross-rolling and the condition of the reheating-facility for the metal to be worked upon.

During the cooling period of the newly cast metal ingot, more or less oxidized rents or crevices on the interior of the ingot result from the tendency of the metal to shrink.

For piercing such ingots advantageously the inner zoneof such ingotis to be reheated relatively to the highest degree, and in order to weld oil such crevices, the importance of thoroughly reheating cold workpieces is important.

The operation of such thorough and costly reheating renders it difiicult the more the ingots increase in diameter.

It istherefore obvious that the manufacturing-costs increase according'to the increaseof size of material used by the known process, on account of the excessive quantity of fuel used and the great loss of metal in the furnace.

Experience has proved that during cooling down, the segregation of sulphur and phosphorus at the interior of ingots gen- It is a well known fact,-

Serial No. 496,833.

erally renders the welding up of crevices difiicult.

In order to overcome these disadvantages, it has been proposed, for manufacturing hollowsor tubes'out of metal while in fluid condition to pour the fluid metal. into special receivers placed above rolls. latter and over a mandrel, the metal should be pressed and rolled after the pasty state of metal is reached.

The nature of such metal in various States of heat is however not in accordance with the.

requirements of the intended operations. and therefore none of such methods could be carried out in practice.

The essence of the present invention is, to meet the distinct requirement of the peculiar nature of tube metal according to the decreasing temperature during the operation.

This simple process is rendered very cheap by making use of the pouring heat in the foundry and thus saving reheating fuel. The quality of tubes obtained is largely improved through the prevention of detrimental crevices in the interior of ingots.

The invention consists of a method for economically piercing metal-ingots into hollow blooms or the like immediately after the metal is poured into moulds and while the interior of the ingot is at a comparatively high temperature and bein correspondingly equalized, suitable for eit er piercing over a central mandrel between cross-rolling piercers or by means of driving piercingmandrels into the centre of the metal while still in moulds or in other receivers and while the interior of the metal is at a welding heat.

In order that this invention may be clearly understood and readily carried into practice reference may be made to the accompanying drawings, in which Figure 1 is a part-sectional elevation illustrating the operation of forming a seamless tube from an ingot arranged between Mannesmann cross rolling rolls; Figure 2 isa part-sectional elevation illustrating the operation of forming a seamless tube while the ingot is still in the mold.

In a convenient embodiment of the invention as shown in Fig. 1, the cast ingot A, after it has cooled down to the stage at which the exterior is firm, but the interior, as in- Through the dicated at the core designated A is still at the temperature at which it can be Welded, is prepared for and entered between a, peri'pheral forming device such as cross rolls C. Whilst the ingot travels over the mandrel B, the rents and crevices in the interior of the ingot are eliminated through the disrupted parts being welded together again so that a homogeneous interior is obtained and the entire hollow body produced is flawless all the way through.

In the pressing arrangement employed, as shown in Fig. 2 the ingot mould D is used as an ingot receiver. A ram E may be applied direct for piercing as to X or a plug F ma be forced through the ingot-metal A by the ram E whilst the metal is in a pasty state at the interior of ingot A. The operation may be performed upon each ingot separately or in groups. Upon plate H is placed mould D covered with a guiding cover J. At the bottom of the mould is inserted a hollow or solid plug G which is forced through the bottom by the ram at the last stage of pressing or piercing.

It will be understood that the expression Welding temperature means a distinct temperature at which the iron or steel becomes weldable, and as the welding heat depends upon the content of carbon and also the purity of the iron or steel alloy, no definite temperature can be stated as being applicable in all cases, since the welding heat or welding temperature varies for each molten metal under treatment.

The hollow body after having been pierced is to be rolled out into tubes in the usual way.

What I do claim as my invention and desire to secure by Letters Patent of the United States is 1. A method of producing hollow bodies from weldable metal, such as steel, consistin in first casting an ingot from molten wtfidable metal; then allowing it to cool until substantially the core retains a plastic, weldable state; and driving a mandrel through the core so as-to produce a hole and to simultaneously weld together into a flawless mass the substance of the body that is rent and creviced in the hollowing operation.

2. A method of producin hollow ingots for the production of seamIess tubes from weldable metal such as steel, consisting in first casting an ingot from molten weldable metal, then allowlng it to 0001 until substantially the core alone retains a plastic, weldable state; and thereupon passing the ingot between cross rollers and simultaneously driving a mandrel through the core so as to produce a hole and at the same time weld together into aflawless mass the substance of the ingot that is rent and creviced in the hollowing and rolling operation.

3. A method of producing hollow blanks for the manufacture of seamless tubes from weldable metal such as steel, consisting in first casting an ingot from molten weldable metal and allowing it to cool until'its transition from a liquid to a solid state is somewhat advanced, while the core still retains a plastic, weldable state; and then driving a mandrel through the core so as to produce a hole and to simultaneously weld together into a flawless mass the substance of the ingot that is rent and creviced in the hollowing operation.

4. A method of producing hollow blanks for the manufacture of seamless tubes from weldable metal such as steel, consisting in first casting an ingot from molten weldable metal and allowing it to cool until the exterior is below a welding temperature, while the core still retains a plastic, weldable state; and then passing the ingot between cross rollers and simultaneously driving a mandrel through the core so as to produce a hole and at the same time weld together into a flawless mass the substance of the ingot that is rent and creviced in the hollowing and rolling operation.

5. A method of producing hollow blanks for the manufacture of seamless tubes from weldable metal such as steel, consisting in first casting an ingot from molten weldable metal and allowing it to cool until its transition from a liquid to a solid state is somewhat advanced, while the core still retains a plastic, weldable state; and thereupon, While defining the external diameter, driving a mandrel through the core so as to produce a hole and simultaneously weld together into a flawless mass the substance of the ingot that is rent and creviced in hollowing and diameter-defining operation.

In testimony whereof I afiix my signature.

THEODOR BECKER. 

